Dynamically balanced relay



June 24, 1947- A. sKRoBlscH DYNMICALLY BALANCED RELAY Filed Sept. 28,1943 Tigri..

/g /6 e 24 /s Patented June 24, 1947 2,422,861 DYNAMICALLY BALANCEDRELAY Alfred Skrobisch, New York, N. Y., assignor to Eastern AirDevices, Inc., Brooklyn, N. Y., a corporation of New York ApplicationSeptember 28, 1943, Serial No. 504,168

6 Claims. (Cl. 175-336) This invention relates to a dynamically balancedrelay.

The prime object of the present invention centers about the provision ofa relay which is nherently insensitive to any linear acceleration ordeceleration, sudden or gradual, in any direction, such as may beencountered in aircraft use.

Relays having dynamically balanced armatures have been suggestedheretofore. So far as I am aware, none of these has been constructed onprinciples which adequately meet the requirements encountered in amoving medium such as an airplane, where high speeds, changes of speedand of direction of movement and accelerations and decelerations of allkinds constitute the normal conditions of travel. To effectively meetthe requirements, all of the moving parts of the relay, namely, thearmature, the controlling spring or springs, and the actuated contact orcontacts should be so constructed and mounted that a substantiallyabsolute dynamic balance is obtained, and in such a way that such partsare movably sensitive only to an acceleration or deceleration which isnot encountered in use. The design and construction of a dynamicallybalanced relay of this nature is the prime desideratum of the presentinvention.

Ancillary objects of the invention include the provision of adynamically balanced relay which is compact, structurally simple and iscapable of ease and certainty of action and operation.

To the accomplishment of these objects and such other objects as mayhereinafter appear, my invention relates to the relay combination assought to be defined in the appended claims and as described in theaccompanying specification taken together with the appended drawings, inwhich:

Fig. 1 is a vertical elevational view of the relay embodying theprinciples of the present invention, this view being shown partly insection taken in the plane of the line |-I of Fig. 2;

Fig. 2 is a plan view thereof;

Fig. 3 is an exploded view of parts thereof;

Fig. 4 is a perspective view of a detail; and

Fig. 5 is a top plan View illustrating the electrical connections of theparts of the relay.

Referring now more in detail to the drawings, the dynamically balancedrelay of the present invention comprises a single electromagnet coil C,the metallic field member therefor generally designated as F, themovable armature A, all housed or contained in a housing or container H,and one or more contact elements generally desig- 2 hated as c1 and c2actuated by the operation of the relay.

The electromagnet coil C comprises a single coil of wire I0 wound andmounted on a bobbin or spool l2, the coil terminating in the leads I4,I4. The metallic field member F forming the magnetic paths for the relaycomprises a core in the form of a, post I6 mounted centrally v(in thebore) of the coil C and a U-shaped piece generally designated as I8, thebranches 20 and 22 of which lie on opposite sides of the coil C and thebase 24 of which lies along the bottom end4 of the coil C. The core i6is attached centrally to the base 24 as by being riveted as at 26thereto. The upper ends 20 and 22 of the branches 20 and 22 form thefield pole pieces for the relay and these preferably extend upwardlysomewhat beyond the vertical dimensions of the armature A. The coil C ismounted so as to snugly fit on the post IE and be supported on andwithin the metallic field member F. The post i6 and the U-shaped pieceI8 are made of a magnet steel.

The movable armature A is located at the other or top end of the coil Cand, following the constructional principles of the present invention,is rotatably mounted about the axis of the core I6. Preferably the postdefining this core extends upwardly sufficiently to mountingly receivethe armature A and the elements carried by the armature, as is mostclearly shown in Fig. l of the drawings. The armature A also preferablycomprises a U-shaped piece generally designated as 28, the base 30 ofwhich is centrally oriflced as at 32 so that the armature is received bythe upper end of the post i6, the said armature being thereby mounted torotate on and about said post I6, the same being spaced from the coil Cby a non-magnetic spacer ring or washer 34.

'The branches 36 and 38 of the U-shaped armature A form pole pieceswhich extend radially in opposite directions from the axis of the coreor post i6 to lie adjacent the field pole pieces 20 and 22' as bestshown in Fig. 2 of th'e drawings. Preferably the field pole pieces 20and 22 and the armature pole pieces 36 and 38 are all equidistantradially from the coil or core axis, all of these pole pieces thereforelying in the same circumference of the relay coil structure as is mostclearly evident from Figs. 2 and 5 of the drawings. When the coil C isenergized, the armature A, assuming its normal position to be that shownin the drawings, is rotatably moved about the core axis in the clockwisedirection as indicated by the arrows in Fig. 2.

For returning the armature A and holding the same in its normal relaydeenergized position as shown in the drawings, the controlling springgenerally designated as S is provided. The spring S is preferably a leafspring flxedly anchored at its center at the axis of the coil C or coreIl, the said spring also exending radially in opposite dlrections fromsaid axis and having its free ends connected to the ends of the amature.Preferably the top of the post I6 is longitudinally and medially slittedas at Il to receive the middle portion 42 of th'e spring S. suchreception being adequate to effect the anchoring o! the spring at thecenter or axis of the post. 'I'he amature pole pieces 36 and 38 are alsovertically slitted as at 4| and 46, respectively, to receive the ends 48and 50, respectively, of the spring S; thereby the free ends of thespring are connected to the armature ends or pole pieces. The armature Aand the parts carried thereby including the spring S are held inposition on the post by means of a split snap spring 52. 'I'hese partsare readily assembled on the post by placing the armature over the post,by then inserting the leaf spring into the post and armature slots, andby then snapping the ring in position.

By means of this recited construction all of the essential movable partsof the relay (as well as the added parts to be described below) embody aconstruction and a mounting which entails absolute symmetry around theaxis of the coil and core. The armature A structurally and positionallyis symmetrical about the coil axis and the controlling spring S is alsostructurally and positionally symmetrical about the same axis. Themagnetic paths are similarly symmetrical about this axis, the paths oithe lines of magnetic force extending up the center post l out radiallyin opposite directions through both arms of the armature A to thearmature pole pieces 36 and 38, and th'en down from the field polepieces 20' and 22'. through both the branches 20 and 22 of the fieldmember, to and through the two arms of the base 24 of the field member,returning to and meeting at the bottom of the center post I6. Thearmature together with its controlling spring (as well as all of th'eparts which it carries) is fully balanced with respect to its own centerabout which it rotates, thus nullii'ying the inertia effect of anychange of speed and any acceleration or deceleration in any `lineardirection, and in fact in any other direction as well except in a rotaryor angular direction about the relay axis (a condition impossible tomeet with in aircraft use). Motion in the vertical direction of therelay is prevented by the collar 3l and the snap ring 52.

The relay parts may be conveniently housed or contained in the housing Hwhich comprises a cylindrical casing coaxial with the coil. This housingmay comprise an aluminum container body provided 'with a top closure 56made preferably of a transparent plastic so that the interior parts maybe visible therethrough as indicated in Fig. 2 of the drawings. Theclosure or cover 56 is-held in position between the inturned flange 58of the casing body and the top ends of the field pole pieces 20' and 22'as best shown in Fig. 1 of the drawings. This closure 56 may be providedwith the ilxed contact parts and the connectors of the relay as will bedescribed further hereinbelow.

The armature A may be supplied or provided with the movable relaycontacts.. To maintain the dynamic balance desired, I preferably employa symmetrically shaped element for carrying the contacts and alsopreferably employ contacts symmetrically disposed thereon, the symmetrybeing about the core axis. This may be accomplished in many ways, theway exemplified com- Drisins the use of an insulating base washer Ilriveted as at l2. C! to the armature A to which is riveted as at ll, Ilthe contact ring Il (made. for example, of Phosphor bronze, etc.)containing the upmandingly mounted contact elements Il. 6l. Aninsulating cover washer 1I, made, for example. of Bakelite or similarmaterial, may then be placed over the contact ring. Thus all of theelements supported by the amature including the two movable contacts arealso dynamically balanced, the construction provided for the relayenabling this to be accomplished.

Cooperating with the armature contacts tl, Il and defining the contactsc1 and ca above referred to, stationary contacts 1I. 1I are provided.which latter are both fixed to and mounted on the housing closure |50 ina manner clearly shown in Figs. 1, 2, 4 and 5 of the drawings, the upperends of these contacts extending outwardly for attaching reception ofconductor leads 14, 1l. In Fig. 5 of the drawings the contact ring Il issymmetricallv represented as a bar l.' which form (illustrating anysymmetrical form) it may take. The closure 5C may also carry in asimilar way the connectors 16, 1i to which the leads Il, Il areconnected interiorly of the casing and to which aterior leads 1l, 1l maybe attached.

The dynamically balanced relay of the present invention, itsconstruction, manner of assembling and the functioning thereof toachieve the main purpose of the invention will. it is believed,'be fullyapparent from the above detailed description thereof. A dynamicallybalanced relay is produced in which an almost absolute dynamic balanceis obtained, and in such a way that all of the moving parts of the relayare movably sensitive only to an acceleration or deceleration of a kindnot encounierable in use. The relay may, therefore, be mounted withcomplete safety in a fast moving medium such as an airplane, where highspeeds, changes of speed and direction of movement and accelerations anddecelerations of all kinds are the normal conditions met with. Inaddition to accomplishing this main Purpose, I have provided a unitwhich is exceedingly compact and which is very simple in construction.This structure, including also the emciency in the magnetic pathsprovided, produces a unit which possesses ease and certainty of actionand operation.

It will be apparent that structural changes may be made within theprinciples of the invention described and which come within the purviewof the invention as deilned in the following claims.

I claim:

l. A dynamically balanced relay comprising an electromagnet coil, ametallic eld forming the magnetic paths therefor consisting of a coremounted centrally of the coil and a U-shaped piece the branches oi whichlie on opposite sides of the coil and the base of which lies along anend of the coil, the core being attached centrally to the base, the endsof said branches forming field pole pieces for the coil, a movablearmature at the other end of the coil rotatably mounted about the axisof said core and having its pole pieces extending radially in oppositedirections from said axis to lie adjacent the field pole pieces, and aspring for said armature anchored fixedly at the axis of said core andalso extending radially in opposite directions from said axis andconnected at its free ends to the ends of said armature.

2. The relay of claim l in which the spring is a leaf spring and inwhich the free ends of the leaf spring are connected to the pole piecesof the armature.

3. A dynamically balanced relay comprisingl an electromagnet coil, ametallic field forming the magnetic paths therefor consisting of a coremounted centrally of the coil and a U-shaped piece the branches of whichlie on opposite sides of the coil and the base o-f which lies along anend of the coil, the core being attached centrally to the base, the endsof said branches forming field pole pieces for the coil, and a movablearmature at the other end of the coil rotatably mounted about the axisof said core and also comprising a U-shaped piece, the base of which ismounted to rotate on and about said core and the branches of which formpole pieces extending radially in opposite directions from said core tolie adjacent the'eld pole pieces, the field pole pieces and the armaturepole pieces being located equi-distant radially from the core axis andlying in the same circumference about the core axis.

4. A dynamically balanced relay comprising an electromagnet coil, ametallic field forming the magnetic paths therefor consistin-g of a coremounted centrally of the coil and a U-shaped piece the branches of whichlie on opposite sides of the coil and the base of which lies along anend of the coil, the core being attached centrally to the base, the endsof said lbranches forming field pole pieces for the coil, a movablearmature at the other end of the coil rotatably mounted about the axisof said core and also comprising a U- shaped piece, the base of which ismounted to rotate on and about said core and the branches of which formpole pieces extending radially in opposite directions from said axis tolie adjacent the field pole pieces, and a spring for the armatureanchored fixedly to said core and also extending radially in oppositedirections from its axis and connected at its free ends to the ends ofthe armature.

5. A dynamically balanced relay comprising an electromagnet, a metallicfield forming the magnetic paths therefor consisting of a post' and a U-shaped piece the branches of which lie on opposite sides of said postand to the base of which the said post is centrally attached, the endsof said branches forming field pole pieces, an armature rotatablymounted about the axis of said post and having its pole pieces extendingradially in opposite directions from said axis to lie adjacent the eldpole pieces, and a spring for said armature anchored iixedly at the axisof the post and also extending radially in opposite directions from saidaxis and connected at its free ends to the ends of the armature.

6. A dynamically balanced relay comprising an electromagnet coil, ametallic field forming the magnetic paths therefor consisting of a coremounted centrally of the coil and a U-shapedpiece the branches of whichlie on opposite sides of the coil and the base of which lies along anend of the coil, the core being attached centrally to the base, the endsof said branches forming iield pole pieces for the coil, a movablearmature at the other end of the coil rotatably mounted about the axisof said core and having its pole pieces extending radially in oppositedirections from said axis to lie adjacent the field pole pieces, thefield pole pieces and the armature pole pieces being locatedequi-distant radially from the core axis, and a cylindrical casingcoaxial with said core enclosing the relay, the said casing beingprovided with a cover held between the. casing top and the field polepieces. ALFRED SKROBISCH.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 2,310,138 Whittaker Feb. 2,19431,763,003 Mead June 10, 1930 1,920,135 Allen July 25, 1933 1,748,929Woodring Feb. 25, 1930 1,452,925 Nottage Apr. 24, 1923 1,852,232Buchhold Apr. 5, 1932 2,353,756 Price July 18. 1944 FOREIGN PATENTSNumber Country Date 215,679 Great Britain May 15, 1924 y243,432 GermanyFeb. 13, 1912

